Will Saletan writes about politics, science, technology, and other stuff for Slate. He’s the author of Bearing Right.

We don’t yet know who killed this boy. But one thing is clear: The mentality at the heart of terrorism—the willingness to punish many people for the sins of a few—has infected Israel.

Jewish teaching, like Muslim and Christian teaching, forbids deliberate or reckless harm to innocent people. But Israel has long faced terrorist threats on all sides. From bitter experience, it has developed a doctrine of tit for tat, hitting back hard to discourage its enemies from striking again. Together, the terrorism and the reciprocity have led to a policy of limited collective punishment.

One example is Israel’s presumption of geographic responsibility. Under rules announced two years ago by its military chief of staff, attacks in various parts of Israel will result in retaliatory strikes on the nearest enemy, regardless of who staged the attack. If Israel is hit in the south, it will strike Hamas in Gaza. If Israel is hit in the north, it will strike Hezbollah in Lebanon.